Convert refactoring tests to use 'await'.

pkg/analysis_server/test/services/refactoring/abstract_refactoring.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.services.refactoring;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/correction/status.dart';
@@ skipping 56 matching lines @@
    * with the given [path].
    */
   void assertNoFileChange(String path) {
     SourceFileEdit fileEdit = refactoringChange.getFileEdit(path);
     expect(fileEdit, isNull);
   }
 
   /**
    * Asserts that [refactoring] initial/final conditions status is OK.
    */
-  Future assertRefactoringConditionsOK() {
-    return refactoring.checkInitialConditions().then((status) {
-      assertRefactoringStatusOK(status);
-      return refactoring.checkFinalConditions().then((status) {
-        assertRefactoringStatusOK(status);
-      });
-    });
+  Future assertRefactoringConditionsOK() async {
+    RefactoringStatus status = await refactoring.checkInitialConditions();
+    assertRefactoringStatusOK(status);
+    status = await refactoring.checkFinalConditions();
+    assertRefactoringStatusOK(status);
   }
 
   /**
    * Asserts that [refactoring] final conditions status is OK.
    */
-  Future assertRefactoringFinalConditionsOK() {
-    return refactoring.checkFinalConditions().then((status) {
-      assertRefactoringStatusOK(status);
-    });
+  Future assertRefactoringFinalConditionsOK() async {
+    RefactoringStatus status = await refactoring.checkFinalConditions();
+    assertRefactoringStatusOK(status);
   }
 
   /**
    * Asserts that [status] has expected severity and message.
    */
   void assertRefactoringStatus(RefactoringStatus status,
       RefactoringProblemSeverity expectedSeverity, {String expectedMessage,
       SourceRange expectedContextRange, String expectedContextSearch}) {
     expect(status.severity, expectedSeverity, reason: status.toString());
     if (expectedSeverity != null) {
@@ skipping 19 matching lines @@
    * Asserts that [refactoring] status is OK.
    */
   void assertRefactoringStatusOK(RefactoringStatus status) {
     assertRefactoringStatus(status, null);
   }
 
   /**
    * Checks that all conditions of [refactoring] are OK and the result of
    * applying the [Change] to [testUnit] is [expectedCode].
    */
-  Future assertSuccessfulRefactoring(String expectedCode) {
-    return assertRefactoringConditionsOK().then((_) {
-      return refactoring.createChange().then((SourceChange change) {
-        this.refactoringChange = change;
-        assertTestChangeResult(expectedCode);
-      });
-    });
+  Future assertSuccessfulRefactoring(String expectedCode) async {
+    await assertRefactoringConditionsOK();
+    SourceChange change = await refactoring.createChange();
+    this.refactoringChange = change;
+    assertTestChangeResult(expectedCode);
   }
 
   /**
    * Asserts that [refactoringChange] contains a [FileEdit] for [testFile], and
    * it results the [expectedCode].
    */
   void assertTestChangeResult(String expectedCode) {
     // prepare FileEdit
     SourceFileEdit fileEdit = refactoringChange.getFileEdit(testFile);
     expect(fileEdit, isNotNull);
@@ skipping 12 matching lines @@
     CompilationUnit unit = resolveLibraryUnit(source);
     index.indexUnit(context, unit);
   }
 
   void setUp() {
     super.setUp();
     index = createLocalMemoryIndex();
     searchEngine = new SearchEngineImpl(index);
   }
 }